Ошибка в коде преобразования изображения - C#

using System.Drawing;
using Image.Contracts;
using System.Windows.Forms;
using System.Drawing.Imaging;
 
namespace Binarization.Transformation
{
    public class BinarizationTransformation : IImageTransformation
    {
        public BinarizationTransformation()
        {
            BinarizationThreshold = 122;
        }
 
        public string Name
        {
            get
            {
                return "Binarization";
            }
        }
 
        public string Description
        {
            get
            {
                return "Transfroms the input image into binary image.";
            }
        }
 
        public int BinarizationThreshold { get; set; }
 
        public Control UI {
            get
            {
                return _ui ?? (_ui = new BinarizationParameters { numThreshhold = { Value = BinarizationThreshold } });          
            }
        }
        private BinarizationParameters _ui;
 
        private Bitmap GetArgbCopy(System.Drawing.Image sourceImage)
        {
            var bmpNew = new Bitmap(sourceImage.Width, sourceImage.Height, PixelFormat.Format32bppArgb);
            using (Graphics graphics = Graphics.FromImage(bmpNew))
            {
                graphics.DrawImage(sourceImage, new Rectangle(0, 0, bmpNew.Width, bmpNew.Height)
                    , new Rectangle(0, 0, bmpNew.Width, bmpNew.Height), GraphicsUnit.Pixel);
                graphics.Flush();
            }
            return bmpNew;
        }
 
        private Bitmap ApplyColorMatrix(System.Drawing.Image sourceImage, ColorMatrix colorMatrix)
        {
            Bitmap bmp32BppSource = GetArgbCopy(sourceImage);
            Bitmap bmp32BppDest = new Bitmap(bmp32BppSource.Width, bmp32BppSource.Height, PixelFormat.Format32bppArgb);
 
            using (Graphics graphics = Graphics.FromImage(bmp32BppDest))
            {
                ImageAttributes bmpAttributes = new ImageAttributes();
                bmpAttributes.SetColorMatrix(colorMatrix);
 
                graphics.DrawImage(bmp32BppSource, new Rectangle(0, 0, bmp32BppSource.Width, bmp32BppSource.Height),
                    0, 0, bmp32BppSource.Width, bmp32BppSource.Height, GraphicsUnit.Pixel, bmpAttributes);
 
            }
 
            bmp32BppSource.Dispose();
 
            return bmp32BppDest;
        }
 
        public Bitmap brg(System.Drawing.Image sourceImage, int threshold)
        {
            var k = threshold;
            ColorMatrix colorMatrix = new ColorMatrix(new float[][]
 
            {
                new float[] {k, k, k, 0, 0},
                new float[] {k, k, k, 0, 0},
                new float[] {k, k, k, 0, 0},
                new float[] {0, 0, 0, 1, 0},
                new float[] {-k, -k, -k, 0, 0}
            });
 
            return ApplyColorMatrix(sourceImage, colorMatrix);
 
        }
 
        public Bitmap Apply(Bitmap bmpImg)
        {
/*
            Bitmap BinarizationImage = new Bitmap(bmpImg.Width, bmpImg.Height);
 
            BinarizationImage = (brg(BinarizationImage, BinarizationThreshold));
 
            return BinarizationImage;
*/ где-то тут ошибка как я думаю 
        }
    }
}

private void Apply_Click(object sender, EventArgs e)
        {
            var pic =new Bitmap(pictureBox1.Image);
            
            var RGBFilters = new ExtBitmap();
            if (pictureBox1.Image != null)
            {
                pictureBox2.Image = (RGBFilters.ColorBalance(pic,(byte)trcRed.Value, (byte)trcGreen.Value, (byte)trcRed.Value));
                
            }

     public Bitmap Apply(Bitmap bmpImg)
        {
            
            Bitmap BinarizationImage = new Bitmap(bmpImg.Width, bmpImg.Height);
          
                BinarizationImage = (brg(bmpImg,BinarizationThreshold ));
 
            return BinarizationImage;
           
        }